Boiler.



No. 656,536. Patenfed Aug. 21, I900. n. mzmssnns.

B 0| L E B.

(Aiwplication filed Dec. 28, 1899.)

(No Model.)

M val/ ala WITNESSES ms PETERS ca. Pumauwo. WASHINGTON a. c

NITED STATES PATENT Q-FFIGE.

DAVID FITZGIBBONS, OF OSWEGO, NE\V YORK.

BOILER.

SPECIFICATION forming part of Letters PatentN 656,536, dated August 21,1900. Application filed December 28, 1899. Serial No. 741,782. {Nomodel.)

10 all whom it may concern.-

Be it known that I, DAVID FITZGIBBONS, of

Improvements in Boilers, of which the fol-' lowing, taken in connectionwith theaccompanying drawings, is a full, clear, and exact description.

My invention relates to a new construction of steam or hot-water boiler;and it consists in certain features of construction by which the boileris made strong and more durable and more efficient and economical inoperation. Its important feature is the single sheet forming the crownof fire'box and combustion-chamber and rear plate of combustion chamber.

My invention will be better understood by reference to the accompanyingdrawings, in which the same reference-numerals indicate the same partsin all the figures.

Figure I is alongitudinal section of my improved boiler. Fig. II is acorresponding section showing a variation in construction, portionsbeing broken away. Fig. III is a front elevation of the fire-door andair-door. Fig. 1V is an enlarged vertical section thereof. Fig. V is anenlargedvertical section of the cylinder by which gradual closing of theairdoor is effected. Figs. VI and VII are respectively an enlargedvertical section and an elevation, with portions broken away, show in gthe arrangement of the steel ring between the lower edges of the innerand outer shell.

In the drawings, 1 indicates the cylindrical ash-piuformed separate fromthe main portion of the boiler, preferablyof steel, having the. usualdoor2 and an inwardly-extending ledge I 3 for supporting the frontportion of the boiler, whose construction will now be described.

4 indicates the vertical outer shell of the boiler, with the horizontaltube-containing extension 5, and 6 the inner shell forming thesubstantially-cylindrical lower portion or the the space between thelower edges of the inner and outer shells and perforated to receiverivets 12 for securing the parts in position, said ring being preferablycorrugated between the rivets to diminish the weight, as shown in Fig.VII. It will be noticed that these Water-legs 8 8, between the lowerportions of the inner and outer shells, are of substantially-uniformdiameter from top to bottom, neither the inner nor the outer shellsbeing bent for the purpose of connecting them together. I The ring restson theannular ledge 3 of the ash-pit for supporting the boiler.

Thecombined fire-box 7 and combustionchamber 9 are preferably formed, ashere shown, with a cylindrical lower portion and asubstantially-somicircular upper portion, by which construction thegreatest heat is applied directly to'the tubes 15, which extendforwardly over and into the hottest part of the fire, and for thisexposure to the fire the inner shell is particularly adapted by itsspecial construction. To the top of the lower shell 6 is secured frontplate 16, bent into a semicircle, as shown in Fig. I, or bent into ahalf-dome 37, as shown in Fig. II.

The important feature of my inventionis the construction of the plate17, bent at right angles at the point 38 to form the crownsheet of thefire-box and the rear plate of the combustion-chamber.- By making theplate continuous at this point and forming con tinuously the top of thecombustion-chamber I have done away with joints, thicknesses of metal,the, and made the plate stronger. This plate 17 may be riveted to thefront plate at the joint 21, as shown in Fig. I, or, as shown in Fig.II, may be secured at joint 22. to the face-plate l6,bent toward therear in the form of a half-dome 37. The tubes 15 are secured in thevertical portion plate 17 by expanding and beading in the usual manner.Stays 39 39 are provided, extending between the inner and the outershell and bracing the various parts of the boiler. By this constructionand arrangement of plates I have produced a strong and durable boilerand one in which all joints are easily reached for calking, riveting,andrepairing, 23 being the manhole, and 24 24 hand-holes closed by theusual means.

I wish to describe adevice of my invention for opening automatically anair-door and regulating its closing.

40 is the door, provided with usual baffleplate and latch 41.

42 is the air-door, having piston 43, fitting cylinder 44, provided withvent 45 and th umbscrew 46 for regulating escape of air,and withair-hole 47. The piston has the usual checkvalve 48. The air door isautomatically opened when coal is added by rod 49 on latch engaging witharm 50 on air-door, and the air entering mingles with the gases andpromotes perfect combustion, the amount of air entering being regulatedby the speed with which the air-door closes.

The arrangement of steam-drum 55, connected by pipes 56 and 57,respectively, to the horizontal and vertical portion of the steam-spaceis new and particularly effective.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In combination in a steam-generator, an outer'vertical cylindricalshell, a horizontal cylindrical shell connected to about the middle ofthe vertical shell and extending rearwardly therefrom, an inner shellarranged concentrically within the vertical shell, said inner shellhaving a lower cylindrical portion forming a fire-boxand an uppersubstantiallysemicylindrical portion forming a combustion-chamber, thecrown-sheet of the fire-box and the rear plate of the combustion-chamberbeing formed of a single continuous sheet bent at right angles at thepoint 38, and firetubes arranged in said horizontal shell and secured insaid rear plate.

2. In a steam-generator having inner and outer shells an openingtherethrough into the combustion-chamber closed by a fuel-door, a latchfor locking said fuel-door, an air-door closing an air-opening hingedabove said f neldoor, a rod secured to the fuel-door latch and engagingwith said air-door to open the same when the latch is raised, a fixedcylinder, a piston fitting said cylinder and secured to said air-door,and means for permitting the air to escape from said cylinder.

3. In combination in a steam-generator, an outer cylindrical shell, aninner shell concentrically arranged within the outer, a corrugated steelring secured between the lower edges of said shells and having dependingedges, and a separate cylindrical ash-pit section havinganinwardly-extendin g ledge fitted to receive said ring and support saidshells.

4. In combination in a steam-generator, a separate cylindrical ash-pitsection having an inwardly-extending horizontal ledge, an outer verticalcylindrical shell, substantially equal in diameter to the ash-pitsection, an inner shell concentrically arranged within the outer, acorrugated steel ring secured between the lower edges of said shells andhaving a depending edge fitted to said ledge, said inner shell having alower cylindrical portion forming a fire-box, and a contracted upperportion substantially semicircular in crosssection forming acombustion-chamber, a single sheet forming the upper plate of saidfirebox and the rear plate of said combustionchamber, a horizontal,cylindrical shell connected to said vertical shell at about its middleand extending rearwardly therefrom and a series of fire-tubes containedwithin said horizontal shell, extending rearwardly from the verticalshell, and forwardly into said vertical shell where they are secured tosaid plate.

5. In combination in a steam-generator, a separate cylindrical ash-pitsection having an inwardly-extendin g horizontal ledge, an outervertical, cylindrical shell, substantially equal in diameter to theash-pit section, an inner shell concentrically arranged within theouter, a corrugated steel ring secured between the lower edges of saidshells and having a depending edge fitted to said ledge, said innershell having a lower cylindrical portion forming a fire-box, and acontracted upper portion substantially semicircular in cross sectionforming a combustion-chamber, a single sheet forming the upper plate ofsaid firebox and the rear plate of said combustionchamber, the'upperportion of the front plate of said combustion-chamber being bentrearwardly to form a half-dome and being secured to said single sheetalong the upper edges of both, a horizontal, cylindrical shell connectedto said vertical shell at about its middle and extending rearwardlytherefrom, a seriesof fire-tubes contained Within said horizontal shellextending rearwardly from the vertical shell and forwardly into saidvertical shell where they are secured to said plate, and a steam-drumarranged above and parallel to said horizontal tube-containing extensionimmediately behind the upper portion of said vertical shell and pipesconnecting said drum both to the horizontal extension and to the upperportion of the vertical shell.

In testimony whereof I have hereunto signed my name.

DAVID FITZGIBBONS. [L. s] Witnesses:

E. M. WILKINSON, M. T. BRoWNELL.

